Means for preventing and removing boiler scale



June 26, 1934. L. ERENYI 1,964,704

I MEANS FOR PREY 'ENTING AND REMOYiNG BOILER SCALE I Filed May 25. 1932 '41 ffve Q Patented June 26, 1934 UNITED STATES PATENT OFFICE MEANS FOR PREVENTING AND REMOVING BOILER SCALE Ljudevit Ernyi, Zagreb, Yugoslavia In my earlier patents also relating to means for preventing and removing boiler scale, two poles have been employed, the high tension secondary winding of the transformer being con- 5 nected to the anode of the rectifying valve. The

secondary side of the transformer was thus connected with the anode, and on the cathode side a condenser was interposed which acted as a balance to obtain the pulsation of the alternating current so that no electrical currents could arise thereby on the containers to be protected from the formation of scale.

The present invention relates to an apparatus wherein alternating current is led from the secondary side of an alternating current transformer to the anode and cathode of an electron tube, the secondary winding being divided in two parts and the tube being interposed therebetween. The free outer ends of the secondary winding parts are in capacitative connection over condensers of suitable value with the metal containers, boiler or the like to be protected, but

.not in metallic conductive connection therewith.

Owing to this arrangement, the boiler is subjected to the same potential or potential variations as the condensers.

When the primary winding of the transformer is energized an impulse voltage will be impressed on the condensers and thesame impulse voltage is impressed on the boiler which constitutes ,a

part of the condensers without passage of current having to take place or without theexciter system being connected to the metal part of the boiler to be protected.

Owing to this arrangement the boiler is maintained in the above described electric condition by means of alternating current but without direct current connection. A pulsation is effected with the periodic voltage impulse over the alter- 40 nating current network. If, for instance, the rectifier tube is removed and the parts of thesecondary winding connected together, a passage of current through the entire system will immediately take place, the intensity thereof being dependent on the capacity of the condensers. Passage of current through the boiler is rendered impossible by condensers of proper capacity by the action of the rectifying tube. A passage of current is only possible in the event of short circuiting or when the condensers are injured as by breaking down-from insulating resistances. This, however, is rendered impossible by the use of proper condensers and because the two sides very great and, therefore, no flow of current can take place. The novelty resides in the fact that there is no passage of electrical current and no metallic connection between the condenser to be protected and the protective system as well as 66 the network.'

An example of the apparatus for carrying out the method described is illustrated diagrammatically and by way of example in the accompanying drawing.

'1 and 2 are the conductors which supply alternating current to the primary winding 3 of the transformer. 4 is the secondary winding to the transformer, which in this case is divided into two parts so that the one end of the first part of the secondary winding is connected to the condenser C by a conductor 6, while the second end of this part of the secondary winding 4 is connected with the cathode K of the rectifier 5, while one end of the second. part of the secondary winding is connected with a condenser C by means of the conductor 7 and the second end of the same part of the secondary winding 4 is connected to the anode A of the rectifier 5. The condensers 0 and C' are connected through suitas able conductors 6' and 7' with'the object 11 to be protected, for example a steam boiler or the ike.

The accompanying drawingshows only an example of the apparatus with one rectifier, but the apparatus may also be provided with several rectifie'rs or with one rectifier having several anodes and cathodes without departing from the spirit of the invention.

What I claim is:

An apparatus for preventing the' formation of and for removing scale in boilers comprising an alternating current transformer having I a secondary winding divided into two parts, a rectifler connected with one end of each of the winding parts, connections between the opposite ends of the winding parts andthe' boiler, and condensers interposed in said connections.

LJUDEVIT ERENYI. 

